Cooling device



Jan. 23, 1940. A THOMAS l 2,188,089

COOLING DEVICE Filed 00T.. 8, 1936 Patented Jan. 23, 1940 UNITED STATES PATENT A.or-FICE 3Claims.

This invention relates to cooling devices such as those used in refrigerators and in air conditioning machines.

An object is to A continually circulate a liquid refrigerant in a cooling chamber over the whole inner surface' of the chamber unl all of the liquid is vaporized.

An additional object is to regulate the temperature of the refrigerant entering the cooling element. l

A further object is to remove the vapor from a cooling element without allowing the vapor to become superheated;

Other objects will appear in the following specification.

VIn the drawing:

Figure 1 is a side elevation, with end cover plate removed, of a cooling device in which the liquid refrigerant is re-circulated in the cooling enclosure.

Figure 2 is a front elevation,V with front coverfrigerant liquid.

Figure 4 is a plan view of the device shown in Figure 3.

Figure 5 is a cross sectional view of a double compartment conduit which can supply liquid refrigerant and remove vapor at the same time.

Figure 6 is a. fragmentary elevation of a. refrigerant temperature regulator.

In Figures 1 and 2 box |9| has narrow rectangular air slots |92 arranged so that air can pass through the slots from front to rear and thus to give up heat to thin metal walls |93, sealed to the front and rear slotted faces of the box so that the refrigerant therein cannot escape to the atmosphere.

Compressor pump |94, shown diagrammatically, draws refrigerant vapor through perforated hollow channels 203 placed between walls |93 thereby creating lcw pressure in box |9|. These channels lead into manifold 204 passing through walls |93 and sealed to themto prevent leakage. Pipe 205 is connected with manifold 2M and leads the vapor to compressor |94. Pipe 205 is sealed to back 209 of box |9|. A channel 203 is placed in box |9| between each adjacent wall |93 and a number of these channels at different levels may be employed to draw invapor at many points.

Compressor |94 forces the refrigerant vapor into condenser |95, as usual, where it is liqueed.

The liquid is then forced through expansion valve 208 from which it passes to hollow channel |91 to which is fastened hollow plate-like channel |98 with one edge shown partly broken `away to reveal holes |99 in the bottom, so placed that the 5 refrigerant forced through these holes will -be sprayed down on air passage walls |93. The refrigerant liquid will then flow down these walls? by gravity, some of it absorbing suicient heat `from-the metal to become vaporized. The excess 10 liquid will fall into the bottom of box |9| and will be drawn into pipe 201 bypump 206 which will lift the liquid through pipe 202 to force it through manifold and so through perforated pipes 200 so that the refrigerant liquid flows l5 down again over walls |93 to absorb more heat from the air.

Pipes 201 and 202 are of course vsealed to wall 209 to prevent leakage. Pump 206 could be placed in box |9| but it is shown outside so that the 20 heat from the motor driving pump 20E can be more easily dissipated. l

In operation, it will be seen then that the re' frigerant vapor is drawn ou where formedso that it does not become superheated by further contact with the metal cooling surfaces. Fur-A thermore the liquid refrigerant in the box is circulated again and again over the metal cooling surfaces by pump 206 until it is vaporized so that all the heat transferred to the liquid is eiciently used. All of the heat extracted from the air assists in eventually vaporizing the refrigerant.

The amount of refrigerant admitted to box I9| through valve 208 may be regulated by any suitable system or valve 208 may be eliminated and I channel |98 may be a simple pipe leading into box |9| at the bottom, with a iioat valve for e maintaining a constant level of liquid refrigerant.

Such valves are well known and require no description.

This cooling device is particularly efficient since the vapor is not superheated by coming into contact with the cooling surface and therefore the entire cooling surface may be employed entirely inevaporating the liquid refrigerant.

It is desirable to insulate pipe 205 from direct metallic contact with back 209 so heat will not be transferred between cooling surfaces |93 and pipe 205.

As shown. in Figure 3 the cooling element 2M 50 may be in the form of a thin metal conduit of rectangular cross section and forth to form a large surface area within a small space. While this form is shown the element may be coiled into a spiral or bent into any other defolded back and Y sired shape. Vertical channels zl, 216, and 211 are sealed to manifold 218, holes 219, 220 and 221 being provided to conduct refrigerant vapor from one to the other. These channels are also sealed to the back edges of the folds of element 214, holes 222 being provided so that refrigerant vapor can be drawn through them to channels 215, 216 and 211; thence to manifold 218 and from there to compressor 223 through pipe 224 sealed to and connecting with manifold 218. Condenser 224a is provided and refrigerant liquid is forced through pipe 225 to expansion valve 226 and from there to the top edge of element 214 through pipe 210. The liquid then flows lengthwise down the various folds which should be slightly inclined to assist the gravity flow. The element 214 may be inclined toward the rear also toprevent liquid from entering holes 222 which may also be placed above the normal liquid level. Any liquid that reaches the end 221 of the bottom fold will be drawn through pipe 228 by pump 229 and forced up through pipe 231) into the topmost fold 214 again so that the liquidwithin the cooling element will be continually circulated until it is vaporized and drawn olf throughiholes 222.

The top part of conduit 214 is shown as partly broken away to reveal sinuous separator 231 which should be made of metal screening or of a perforated metal sheet. This separator is placed between the upper and lower surfaces of conduit 214 and may be metallicly bonded to them. It is for the double purpose of holding the surfaces apart when folded and to conduct heat from both metal surfaces to all parts of the liquid refrigerant flowing past. Outside fins may also be attached to element 214 and it may likewise have corrugated surfaces to increase the area.

This type of cooling element is/,Very economical to construct. It may be placedin various positions. For instance it may rest upon the folded edges and the liquid can be supplied through a folded perforated pipe in the top edge, the refrigerant flowing across the width of element 214 rather than lengthwise. Many other variations are possible.

In Figure 5 is shown metal tube 231 with perfof through partition 232, without superheat.

As shown in Figure 6, pipe 215 supplying liquid refrigerant to cooling chamber 216 may be surrounded with pipe 211 through which the vapor is withdrawn from the cooling chamber. The

liquid in pipe 215 is then heated by the vapor in pipe 211 to approximately the correct temperature for any pressure in chamber 216. This arrangement may be used with the cooling devices shown in the drawing.

Since the refrigerant is brought to the vapori- Zation temperature, or slightly lower, before it strikes the cooling surfaces, the device will operate eilciently. i

Many changes of detail are possible without departing from the spirit of my invention.

What I claim is:

l. In a cooling device, a cooling element composedof a plurality of opposed surfaces, means for supplying liquid refrigerant to said surfaces, perforated conduits between said surfaces, and means for withdrawing refrigerant vapor from said element through said conduits.

2. A cooling element in an evaporator for conducting refrigerant, said element comprising a conduit with a lower channel for conducting liquid refrigerant and an upper perforated channel for eXitof refrigerant vapor.

3. In a cooling device, a cooling element composed of a plurality of inclined surfaces, means for supplying liquid refrigerant to the upper portions of said surfaces, perforated conduits oetween said surfaces, and means for withdrawing refrigerant Vapor from said element through said conduits.

ALBERT G. THOMAS. 

